Thoracic and abdominal evoked potentials were studied in five normal volunteers. The purpose of this study was to establish a method of somatosensory evoked potentials which would: (1) establish definition of normative waveform patterns and component overlying the regions of the scalp and spine upon electrical stimulation of both thoracic and abdominal nerves; (2) determine the central conduction times in normal controls upon electrical stimulation of both thoracic and abdominal nerves; (3) to define the optimal stimulation sites, intensities, and rates upon stimulation of the thoracic and abdominal nerve in normal volunteers. These goals have been accomplished. The findings should be useful for evaluation of patients with spinal cord dysfunction.